GW200105 and GW200115 were identified as NSBH mergers based on the mass estimate of the lighter companion in the binary as \(\lbrace  1.9^{+0.3}_{-0.2}~M_{\odot },\, 1.5^{+0.7}_{-0.3}~M_{\odot } \rbrace \)  respectively. The masses of the heavier companions were estimated as \(\lbrace  8.9^{+1.2}_{-1.5}~M_{\odot },\, 5.7^{+1.8}_{-2.1}~M_{\odot } \rbrace \)  respectively. The spin magnitude of the heavier companion for GW200105 was estimated to be below 0.23 at the 90% credible level and for GW200115 the spin had support for the negative spin projection with respect to the orbital angular momentum plane at 88% probability [1]}. As expected, given the high mass ratio, the tidal deformation and spin of the secondary object were difficult to measure and could not confirm the presence of a NS. Tidal disruption for these events was deemed to be unlikely, due to the high mass ratio and low positive aligned spin components [1]}, [3]}. The inclusion of memory for these events is not particularly helpful here. As can be seen from Fig. REF , for mass ratios greater than 3 the contribution of memory is negligible for the LIGO detectors at its design sensitivity. However, it should be noted that for the future generation of GW detectors, especially Cosmic Explorer, memory will be a necessary feature for distinguishing such events with high confidence as NSBH or BBH binaries.
